Real-time haptic model for soft tissue deformation in surgery simulation

The modelling and simulation of deformable objects is a challenging topic in the field of haptic rendering between human and virtual environment. In this paper, a novel and efficient layered rhombus-chain-connected haptic deformation model based on physics is proposed for an excellent haptic rendering. During the modelling, the accumulation of relative displacements in every chain structure unit in each layer is equal to the deformation on the virtual object surface, and the resultant force of corresponding springs is equivalent to the external force. The layered rhombus-chain-con- nected model is convenient and fast to calculate, and can satisfy real-time requirement due to its simple nature. Simulation experiments in virtual human liver based on the proposed model are con- ducted, and the results demonstrate that our model provides stable and realistic haptic feeling in real time. Meanwhile, the display result is vivid.     

Dehydration melting of UHP eclogite and paragneiss in the Dabie orogen: Evidence from laboratory experiment to natural observation

Dehydration melting of subducted continental crust is significant during exhumation, and its study from both experimental and petrological observations is of great importance to our understanding of continental geodynamics. Dehydration melting experi- ments were carried out on ultrahigh-pressure （UHP） eclogite from Bixiling in the Dabie orogen using a piston cylinder at 1.5-3.0 GPa and 800-950℃ to investigate partial melting of eclogite induced by phengite breakdown. The phengite-bearing eclogite started to melt at T≤800-850℃ and P=1.5-2.0 GPa and produced about 3% granitic melt. The products of dehydration melting vary with temperature and pressure. Such results provide valuable constraints on the micro-texture related to partial melting of UHP rocks in the Dabie-Sulu orogenic belt. Three types of polyphase inclusions were identified in garnet from the Shuanghe UHP eclogite. K-feldspar and quartz inclusions are interpreted to represent the products of segregation and crystallization of minor amounts of melt that formed during dehydration melting of phengite by the inferred reaction Phengite＋Omphacite＋Quartz Amphibole_＋Garnet＋Melt （K-feldspar＋Quartz＋Plagioclase）. Polyphase inclusions of phengite and K-feldspar＋Quartz inclusions were also found in zoisite/clinozoisite and garnet from the Shuanghe garnet-bearing paragneiss. These polyphase inclusions pro- vide evidence for a continuous process from sub-solidus dehydration to partial melting within the UHP gneissic rocks. The com- positional variation of garnets demonstrates that breakdown of epidote-group minerals may have played a crucial role during de- hydration melting reaction of phengite. The Ti-in-zircon thermometry and Si content of phengite in zircon suggest that partial melting would occur at 783-839℃ and 2.0-2.5 GPa. Therefore, both experimental results and petrological observations indicate that dehydration melting and fluid activity within the Dabie UHP rocks at micro-scale are controlled by the breakdown of phengite.     

Sodium arsenite reduces severity of dextran sulfate sodium-induced ulcerative colitis in rats

The histopathological features and the associated clinical findings of ulcerative colitis （UC） are due to persistent inflammatory response in the colon mucosa. Interventions that suppress this response benefit UC patients. We tested whether sodium arsenite （SA） benefits rats with dextran sulfate sodium （DSS）-colitis. The DSS-colitis was induced by 5% DSS in drinking water. SA （10 mg/kg; intraperitoneally） was given 8 h before DSS treatment and then every 48 h for 3 cycles of 7, 14 or 21 d. At the end of each cycle rats were sacrificed and colon sections processed for histological examination. DSS induced diarrhea, loose stools, hemoccult positive stools, gross bleeding, loss of body weight, loss of epithelium, crypt damage, depletion of goblet cells and infiltration of inflammatory cells. The severity of these changes increased in the order of Cycles 1, 2 and 3. Treatment of rats with SA significantly reduced this severity and improved the weight gain.     

Gas chromatographic method for the determination of hexaconazole residues in black tea

A highly reliable, quantitative and sensitive analytical method for determining the residues of the fungicide, hexaconazole in black tea is described. The proposed method is based on liquid-liquid extraction followed by gas chromatographic determination, using nitrogen phosphorus detector （GC-NPD） for the identification and quantitation of hexaconazole. The most appropriate solvent mixture for extracting hexaconazole residues from black tea was n-hexane：acetone at 1 ：1 （v/v）. The extract was cleaned up by adsorption column chromatography using activated florisil. Performance of the method was assessed by evaluating quality parameters such as recovery value, repeatability, reproducibility, linearity and limits of detection and quantitation. When the method was assessed for repeatability, the percentage of recovery ranged between 86% and 96% while the relative standard deviation was between 0.30% and 2.35%. In studies on reproducibility the recovery ranged from 81% to 85% and relative standard deviation from 1.68% to 5.13%, implying that the method was reliable. A field trial was conducted to verify the application of this method with real samples. Results prove that the validated method was suitable for extracting hexaconazole residues.     

Optimization for entransy dissipation minimization in heat exchanger

A common of two-fluid flow heat exchanger, in which the heat transfer between high- and low-temperature sides obeys Newton＇s law [q∝△（T）], is studied in this paper. By taking entransy dissipation minimization as optimization objective, the optimum parameter distributions in the heat exchanger are derived by using optimal control theory under the condition of fixed heat load. The condition corresponding to the minimum entransy dissipation is that corresponding to a constant heat flux density. Three kinds of heat exchangers, including parallel flow, condensing flow and counter-flow, are considered, and the results show that only the counter-flow heat exchanger can realize the entransy dissipation minimization in the heat transfer process. The obtained results for entransy dissipation minimization are also compared with those obtained for entropy generation minimization by numerical examples.     

A preliminary study on the teratogenesis of dexamethasone and the preventive effect of vitamin B12 on murine embryonic palatal shelf fusion in vitro

Excessive dexamethasone （Dex） administrated into pregnant mice during critical periods of palatal development can produce a high incidence of cleft palate. Its mechanisms remain unknown. Vitamin B12 has been shown to antagonize the teratogenic effects of Dex, which, however, remains controversial. In this study, we investigated the effects of Dex and vitamin B12 on murine embryonic palatal shelf fusion using organ culture of murine embryonic shelves. The explanted palatal shelves on embryonic day 14 （E14） were cultured for 24, 48, 72 or 96 h in different concentrations of Dex and/or vitamin B 12. The palatal shelves were examined histologically for the morphological alterations on the medial edge epithelium （MEE） and fusion rates among different groups. It was found that the palatal shelves were not fused at 72 h or less of culture in Dex group, while they were completely fused in the control and vitamin B 12-treated groups at 72 and 96 h, respectively. The MEE still existed and proliferated. In Dex＋vitamin B12 group the palatal shelves were fused at each time point in a similar rate to controls. These results may suggest that Dex causes teratogenesis of murine embryonic palatal shelves and vitamin B12 prevents the teratogenic effect of Dex on palatogenesis on murine embryos in vitro.     

Investigation of stressful life events in patients with systemic sclerosis

Objective： To assess the occurrence of stressful life events in the year before the initiation of systemic sclerosis. Methods： A consecutive series of 40 patients with systemic sclerosis （mean age （56.3±11.9） years, mean disease duration （4.3±3.1） years; 32 females and 8 males）, including 28 with diffuse cutaneous scleroderma and 12 with limited cutaneous scleroderma, were evaluated, A control group of 40 healthy subjects free of systemic sclerosis also was included. Socioeconomic status was investigated and Paykel＇s interview for recent life events （a semi-structured research interview covering 64 life events） was conducted. Results： Patients with systemic sclerosis showed higher percentages of lower education （72.5%） and working class （82.5%）, and reported more stressful life events （P〈0.05）, such as exits （P〈0.05）, undesirable events （P〈0.01）, and uncontrolled events （P〈0.001）, when compared with the control. More events that had an objective negative impact （P〈0.001） were also reported in systemic sclerosis patients than in the control. These results are in accordance with a multifactorial model of pathogenesis in systemic sclerosis. Conclusion： We reported a strong relationship between stressful life events and the initiation of systemic sclerosis. Our findings are consistent with current understanding of the extensive links of behavioral responses to stress with neurophysiological and biochemical processes.     

Friendship between Aziz and Fielding in the Novel of A Passage to India

Forster＇s 1924 masterpiece, A Passage to India, is a novel about preconceptions and misconceptions and the desire to overcome the barrier that divides East and West in colonial India. His famous phrase, ＂only connect,＂ stresses the need for human beings to overcome their hesitancy and prejudices and work towards realizing affection and tolerance in their relations with others. But when he turned to colonial India, where the English and the Indians stare at each other across a cultural divide and a history of imbalanced power relations, mutual suspicion, and ill will, Forster wonders whether connection is even possible.     

Changes of tear film and tear secretion after phacoemulsification in diabetic patients

Objective： To evaluate tear film stability and tear secretion in patients with diabetes after phacoemulsification. Methods： Twenty-five diabetic cataract patients and 20 age-matched non-diabetic cataract patients as control underwent phacoemulsification. Tear film break-up time （TFBUT）, Schirmer I test （SIT）, corneal fluorescein staining, and dry eye symptoms were measured pre- and postoperatively. Results： Diabetics had a decreased preoperative TFBUT and SIT. TFBUT was reduced on Day 1 and recovered on Day 180 postoperatively in both groups. SIT was increased after phacoemulsification, but returned to preoperative levels by Day 180 in non-diabetics, whereas it was lower than preoperative level in diabetics. Positive corneal fluorescein staining was elevated in both groups, and returned to preoperative levels only in controls. Dry eye symptoms were similar to fluorescein staining in both groups. Conclusion： Tear secretion was reduced in diabetic cataract patients after phacoemulsification, which worsened dry eye symptoms and predisposed those patients to ocular damage.     

Science Letters： A synthetic Toll-like receptor 2 ligand decreases allergic immune responses in a mouse rhinitis model sensitized to mite allergen

It has been proposed that activation of Toll-like receptors （TLRs） plays crucial roles in the polarization of adaptive immune responses. A synthetic Toll-like receptor 2 （TLR2） ligand, Pam3CSK4, has been reported to modulate the balance of Th1/Th2 responses. We evaluated the modulation effect of Pam3CSK4 on allergic immune response in a mouse rhinitis model sensitized to house dust mite allergen （HDM）. Mice were sensitized and challenged with Dermatophagoidesfarinae allergen （Der f）, and then the allergic mice were treated by Pam3CSK4. Nasal allergic symptoms and eosinophils were scored. Der f-specific cytokine responses were examined in the splenocytes and bronchoalveolar lavage fluid （BALF）. Serum level of total IgE was also detected. After establishing a mouse allergic rhinitis model with HDM, we have showed that Pam3CSK4 treatment not only ameliorated the nasal allergic symptoms remarkably but also decreased the eosinophils and total inflammation cells in BALF significantly. Analysis of cytokine profile found that IFN-7 released from either BALF or stimulated splenocytes increased markedly in Pam3CSK4-treated mice, while IL-13 decreased significantly. Moreover, serum level of total IgE was significantly lower in Pam3CSK4-treated mice than in the untreated. Thus, in an allergic rhinitis mouse model developed with HDM, Pam3CSK4 was shown to exhibit an antiallergic effect, indicating its potential application in allergic diseases.     

Effects of over-expressing resistin on glucose and lipid metabolism in mice

Resistin, a newly discovered peptide hormone mainly secreted by adipose tissues, is present at high levels in serum of obese mice and may be a potential link between obesity and insulin resistance in rodents. However, some studies of rat and mouse models have associated insulin resistance and obesity with decreased resistin expression. In humans, no relationship between resistin level and insulin resistance or adiposity was observed. This suggests that additional studies are necessary to determine the specific role ofresistin in the regulation of energy metabolism and adipogenesis. In the present study, we investigated the effect of resistin in vivo on glucose and lipid metabolism by over-expressing resistin in mice by intramuscular injection of a recombinant eukaryotic expression vector pcDNA3.1-Retn encoding porcine resistin gene. After injection, serum resistin and serum glucose （GLU） levels were significantly increased in the pcDNA3.1-Retn-treated mice; there was an obvious difference in total cholesterol （TC） level between the experiment and the control groups on Day 30. In pcDNA3.1-Retn-treated mice, both free fatty acid （FFA） and high density lipoprotein （HDL） cholesterol levels were markedly lower than those of control, whereas HDL cholesterol and triglyceride （TG） levels did not differ between the two groups. Furthermore, lipase activity was expressly lower on Day 20. Our data suggest that resistin over-expressed in mice might be responsible for insulin resistance and parameters related to glucose and lipid metabolism were changed accordingly.     

A novel thioredoxin reductase inhibitor inhibits cell growth and induces apoptosis in HL-60 and K562 cells

Human thioredoxin reductase （TrxR） system is associated with cancer cell growth and anti-apoptosis process. Effects of 1,2-[bis（1,2-benzisoselenazolone-3（2H）-ketone）]ethane （BBSKE）, a novel TrxR inhibitor, were investigated on human leukemia cell lines HL-60 and K562. BBSKE treatment induced cell growth inhibition and apoptosis in both cell lines. Apoptosis induced by BBSKE is through Bcl-2/Bax and caspase-3 pathways. Ehrlich＇s ascites carcinoma-bearing mice were used to investigate the anti-tumor effect of BBSKE in vivo. Tumor-bearing mice treated with BBSKE showed an increase of life span with a comparable effect to cyclophosphamide （CTX）. These results suggest a potential usage of BBSKE as a therapeutic agent against non-solid tumors.     

Continuous on-line adaptation of the rotor time constant in FOC induction machine system

Rotor time constant is an important parameter for the indirect lleld oraentateO control of mauc- tion motor. Incorrect rotor tittle constant value will cause the flux observer generating a wrong angu- lar orientation of the rotor field. A new approach serves for rotor time constant on-line adaptation by setting the stator current to be zero for a short period. A smooth eorrector is designed to prevent ab- normal detection result from making adaptation. Impact of zero current duration on detection error and rotor speed is analyzed by experiments.     

A survey on porcine circovirus type 2 infection and phylogenetic analysis of its ORF2 gene in Hangzhou,Zhejiang Province,China

Porcine circovirus type 2 （PCV2） is closely related to the postweaning multisystemic wasting syndrome （PMWS）. In this study, the pig serum and tissue samples collected from different regions of Hangzhou District in Zhejiang Province of China between 2003 and 2005 were analyzed by enzyme-linked immunosorbent assay （ELISA） for PCV2 antibody and by polymerase chain reaction （PCR） for ORF2 gene. The results show that out of 1250 randomly collected serum samples, 500 sera （40%） were seropositive for PCV2. PCR results demonstrate that Hangzhou PCV2 with more than 50% Chinese PCV2 strains and French PCV2 formed Cluster A. Only one PCV2 from Hangzhou belonged to Cluster B with some other Chinese PCV2 and Netherlands＇s isolates. Cluster C consisted of PCV2 isolates from China, US, Canada, UK and Germany. The results indicate that the PCV2 infection was widespread in Hangzhou.     

Optimal time for mesenchymal stem cell transplantation in rats with myocardial infarction

Background： Bone marrow mesenchymal stem cell （MSC） transplantation is a promising strategy in the treatment of myocardial infarction （MI）. However, the time for transplanting cells remains controversial. The aim of this study was to find an optimal time point for cell transplantation. Methods： MSCs were isolated and cultured from Sprague-Dawley （SD） rats. MI model was set up in SD rats by permanent ligation of left anterior descending coronary artery. MSCs were directly injected into the infarct border zone at 1 h, 1 week and 2 weeks after MI, respectively. Sham-operated and MI control groups received equal volume of phosphate buffered saline （PBS）. At 4 weeks after MI, cardiac function was assessed by echocardiography; vessel density was analyzed on hematoxylin-eosin stained slides by light microscopy; the apoptosis of cardiomyocytes was evaluated by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling （TUNEL） assay; the expressions of proteins were analyzed by Western blot. Results： MSC transplantation improved cardiac function, reduced the apoptosis of cardiomyocytes and increased vessel density. These benefits were more obvious in 1-week group than in 1-h and 2-week groups. There are more obvious increases in the ratio of bcl-2/bax and the expression of vascular endothelial growth factor （VEGF） and more obvious decreases in the expression of cleaved-caspase-3 in 1-week group than those in other two groups. Conclusion： MSC transplantation was beneficial for the recovery of cardiac function. MSC transplantation at 1 week post-MI exerted the best effects on increases of cardiac function, anti-apoptosis and angiogenesis.     

Design of 15 Gb/s inductorless limiting amplifier with RSSI and LOS indication in 65nm CMOS

A limiting amplifier IC implemented in 65 nm CMOS technology and intended for high-speed optical fiber communications is described in this paper.The inductorless limiting amplifier incorporates5-stage 8 dB gain limiting cells with active feedback and negative Miller capacitance,a high speed output buffer with novel third order active feedback,and a high speed full-wave rectifier.The receiver signal strength indictor(RSSI) can detect input signal power with 33 dB dynamic range,and the limiting amplifier features a programmable loss of signal(LOS) indication with external resistor.The sensitivity of the limiting amplifier is 5.5mV at BER = 10 ~(-12) and the layout area is only 0.53 ×0.72 mm because of no passive inductor.The total gain is over 41 dB,and bandwidth exceeds12 GHz with 56 mW power dissipation.     

Spatial distribution of Cd and Cu in soils in Shenyang Zhangshi Irrigation Area （SZIA）, China

Heavy metal contamination of soils, derived from sewage irrigation, mining and inappropriate utilization of various agrochemicals and pesticides, and so on, has been of wide concern in the last several decades. The Shenyang Zhangshi Irrigation Area （SZIA） in China is a representative area of heavy metal contamination of soils resulting from sewage irrigation for about 30 years. This study investigated the spatial distribution and temporal variation of soil cadmium （Cd） and copper （Cu） contamination in the SZIA. The soil samples were collected from the SZIA in 1990 and 2004; Cd and Cu in soils was analyzed and then the spatial distribution and temporal variation of Cd and Cu in soils were modeled using Kriging methods. The results show that long-term sewage irrigation had caused serious Cd and Cu contamination in soils. The mean and the maximum of soil Cd are markedly higher than the levels in second grade standard soil （LSGSS） in China, and the maximum of soil Cu is close to the LSGSS in China in 2004 and is more than the LSGSS in China in 1990. The contamination magnitude of soil Cd and the soil extent of Cd con- tamination had evidently increased since sewage irrigation ceased in 1992. The contamination magnitude of soil Cu and the soil extent of Cu contamination had evidently increased in topsoil, but obviously decresed in subsoil. The soil contamination of Cd and Cu was mainly related to Cd and Cu reactivation of contaminated sediments in Shenyang Xi River and the import of Cd and Cu during irrigation. The eluviation of Cd and Cu in contaminated topsoil with rainfall and irrigation water was another factor of temporal-spatial variability of Cd and Cu contamination in soils.